Answer

Using Regex in Playwright Assertions

In Playwright, you can use the toMatch method to check if a string value matches a regular expression. Here's how you can do it:

let value = "This is an example string";
expect(value).toMatch(/example/);

This will check if the word "example" is present in the value string.

Other Assertion Methods in Playwright

Playwright also provides other assertion methods. For instance, toHaveCSS lets you check if an element has a specific computed CSS style. Here's an example:

expect(await page.locator('.my-element')).toHaveCSS('display', 'none');

Another useful assertion is toHaveCount, which checks if a locator resolves to an exact number of DOM nodes. This is especially useful when dealing with lists or tables.

expect(await page.locator('.list-item')).toHaveCount(5);

Advanced Features for Assertions

Playwright also offers advanced features for assertions like asynchronous polling and custom retry intervals. These features help you handle flaky network requests or slow-loading elements. You can learn more about these in the Exploring the Various Retry APIs of Playwright for Robust Testing blog post.

In summary, Playwright offers a variety of assertion methods and advanced features to help you write more robust and reliable tests.